I'm Stage 2+ in my RWD 335, which I track a few days a year (so getting a FMIC was a necessity), but our family car luckily has also got an N54 engine (535 wagon), which is just Stage 1 right now, and it got me thinking if it would be worth it upgrading it to 2+ also...

To keep it apples to apples, and the fact that the 335 is RWD whereas the 535 is AWD, I wanted to get approximate crank HP numbers, rather than at the wheels.

Here is my thinking: I think I've read that stage 1 Aggressive in the 335 will give you about a 75 HP bump to 375, and stage 2+ would be about 425. Is that about right?

To go from stage 1 to 2+, I'd be into it about $2k for the DP's and FMIC and install, so if the numbers above are right, I guess I have to ask myself if it's worth it spending $2k for a 50 CHP gain...

Yea assuming drivetrain loss of something like 13-15%; that gets you in the 360 or so WHP area. For a FBO pump gas car, that sounds about right to me on your “average” dynojet.

But as you know first-hand, the gains aren’t just in terms of max power delta. There is a modest gain in area under the curve, and there are obvious hardware benefits (cooler IATs, cooler EGTs, etc etc). So it’s not just “is X dollars worth X BHP”

I'm Stage 2+ in my RWD 335, which I track a few days a year (so getting a FMIC was a necessity), but our family car luckily has also got an N54 engine (535 wagon), which is just Stage 1 right now, and it got me thinking if it would be worth it upgrading it to 2+ also...

To keep it apples to apples, and the fact that the 335 is RWD whereas the 535 is AWD, I wanted to get approximate crank HP numbers, rather than at the wheels.

Here is my thinking: I think I've read that stage 1 Aggressive in the 335 will give you about a 75 HP bump to 375, and stage 2+ would be about 425. Is that about right?

To go from stage 1 to 2+, I'd be into it about $2k for the DP's and FMIC and install, so if the numbers above are right, I guess I have to ask myself if it's worth it spending $2k for a 50 CHP gain...

Thoughts and comments and corrections welcome.

Hit me up and i'll give you a great deal on parts. Much lower than you estimated.

Yea assuming drivetrain loss of something like 13-15%; that gets you in the 360 or so WHP area. For a FBO pump gas car, that sounds about right to me on your “average” dynojet.

But as you know first-hand, the gains aren’t just in terms of max power delta. There is a modest gain in area under the curve, and there are obvious hardware benefits (cooler IATs, cooler EGTs, etc etc). So it’s not just “is X dollars worth X BHP”

Good point that gains aren't just in peak HP, but at least to start with, I know that the numbers I put out are about right for crank peak HP. I already know the biggest power bump bang/buck is the tune, where for like $700, you get the 75 CHP.

Just debating whether it's worth like $2,000 to go stage 2+ or not and how much I'd gain from it. No E gas here unfortunately, so no potential for that, and won't ever run race gas in that car.

Dp should run 300-500 unless you go AR. FMIC are under 500 also. installation shouldnt be 1000. id expect 100-250 at most.

OK, let's do some basic math which you clearly have not done... I am obviously not quoting some Ebay special DP's and FMIC, when I say what it would cost, and am speaking from experience as this is what I bought already.

Install for both DP's and intercooler for "100 to 250 at most"??? What, you have a monkey working at the shop who gets paid $20 to $50 an hour? Or you have magic hands and can do it all in like 2 to 3 hours?

It'll take 4 to 5 hours to do them best case, depending on how many times the shop has done it. AR and AMS's own documentation say to allow for that much time even.

My shop is very good, and charges $100 an hour.

So take $200 off my estimate even if you really want. Still comes to $1800 all in best case.
.
.
And these are 335 numbers too. If you had read my first post, you'd see I'm talking about doing this for the 535, whose stuff costs even more! So I'm in for $2,000 in parts alone, since I think AR is the only one that makes DP's for it at $1,000, and Evolution Racewerks for the FMIC at another $1,000.
.
.

There are several venders on here that sell downpipes for under 500 and at least one that I know of that sells ICs for under 500 as well. I do agree that the labor estimates were grossly low for a dp install though. It cost me ~300 to have them put in and my shop only charges 85 an hour and charges actual hours not book hours.

__________________

"And just one question I might ask yah, and it might sound like A disaster, can you make this thing go faster?"

There are several venders on here that sell downpipes for under 500 and at least one that I know of that sells ICs for under 500 as well. I do agree that the labor estimates were grossly low for a dp install though. It cost me ~300 to have them put in and my shop only charges 85 an hour and charges actual hours not book hours.

He needs 535i downpipes though. I think only AR sells those. ---> Which means BOAT, Bust out another thousand. ($1022 Retail to be exact).

Edit- Actually BMS sells "dr euro 535i downpipes" for $699 but I never heard of them and don't how they fit. They also have a pretty nasty cut in them.

It still amazes me how cheap so many members are when modding these cars. It's just something I've never experienced on other platforms. Is it the amount of power that can be gained at a relatively low cost from tuning alone that gives everyone this mentality, or what? Or is it that these cars are now being bought and modded by a demographic with less disposable income? I don't mean this as an insult or knock on anyone in particular -- it's just something I'm intrigued by.

On a side note, installing a set of downpipes on an all-wheel drive 5-Series is a pain in the ass. I don't have All-Data in front of me right now, but I bet book time is ~5 hours just for the cat/downpipe install on that car. And an aftermarket intercooler install for $100? That's a hell of a deal if the work quality is good. Most reputable BMW shops are $100+ an hour. I know I wouldn't install the AMS intercooler I put on my car for anybody @ 1 hour of labor.

With most things in this world, you really do get what you pay for in one way or another. That's my experience with cars, anyway.

Now that I got that out of my system, my car made just a little under 400 rwhp (395, I think) running the OTS Stage 2+ Aggressive mapping. This was a rear wheel drive car through the 6AT trans. I did have E30 in the tank (91 octane + 4 gallons of E85) at the time -- and the fuel scalers were altered for it -- but otherwise it was the standard map.

I don't think there's that big of a difference in power loss on the X-drive cars, but I could be wrong. Trying to think of things in crank HP just makes it more confusing, IMO. Keep in mind that BMW's crank HP rating is probably on the conservative side as well.

I just want to chime in and say it took me ~10 hours the first time I did 535 downpipes. Total pita. Now I knock it out in about 3. I still swear I'll never do them again time too. I don't think dr euro pipes will fit an XI either, I believe AR offers the only "I" and "XI" models.

It still amazes me how cheap so many members are when modding these cars. It's just something I've never experienced on other platforms. Is it the amount of power that can be gained at a relatively low cost from tuning alone that gives everyone this mentality, or what? Or is it that these cars are now being bought and modded by a demographic with less disposable income? I don't mean this as an insult or knock on anyone in particular -- it's just something I'm intrigued by.

On a side note, installing a set of downpipes on an all-wheel drive 5-Series is a pain in the ass. I don't have All-Data in front of me right now, but I bet book time is ~5 hours just for the cat/downpipe install on that car. And an aftermarket intercooler install for $100? That's a hell of a deal if the work quality is good. Most reputable BMW shops are $100+ an hour. I know I wouldn't install the AMS intercooler I put on my car for anybody @ 1 hour of labor.

With most things in this world, you really do get what you pay for in one way or another. That's my experience with cars, anyway.

What really concerns me is how cheap some people are with meth and fueling sometimes

Given what I'm reading about the DP's, looks like I'm going to pass on them.

Now I have to see what sort of power gains there are going from stage 1 aggressive to stage 1+ aggressive, with a FMIC. Any ideas? I'm sure it's in the forums, but not in an easy to spot place. Most Cobb dynos I've seen compare 2+ to 1 and stock.

PS When doing the math (correct me if I'm wrong), it's hard to justify getting it though... A nice Cobb tune runs about $750, for which you'll get around 75 HP increase (not at the wheels...)

Whereas with a FMIC, I'll be into it $1500 all in probably, and I might get 25 to 30 more HP, though I'm sure the power curve will also be better (I know it's not just the peak number that counts). Since I don't plan on tracking the car, or ever adding meth to it, I wonder if it's worth doing it...

So I'm thinking I might be better off spending that money elsewhere to get more enjoyment out of the car, like on swaybars, and other things.

Personally, I'd do the intercooler upgrade in a heartbeat. Obviously, it doesn't give you the hp gains / $$$ that tuning does, but nothing is going to match that. That was kind of my point above.

When I was still running OTS 91 octane maps, switching from stage 1 to stage 1+ made quite the difference. Sorry, I don't have any dynos for that mapping to give you any actual numbers. If you look at the OTS Cobb maps in ATR, you'll see some nice load increases (at least in the midrange) with the + maps.

Besides the extra power from the tuning, you'll get more consistency on the street. Intercoolers are win/win if you ask me. Downpipes have some trade-offs IMO, but I don't think you have anything to lose with a FMIC upgrade.